Photographic paper.



P. G. WILCOX.

PHOTOGRAPHIG PAPER. APPLICATION FILED .TUNE4, 1912.

Patented Feb. 11, 1913.

wi /76,072 M wzin 662560:

FRANK G. WILGOX, OF KANSAS CI'IY, MISSOURI, ASSIGNOR OF THREE-FOURTHS T WILLIAM C. REN'FROW, OF KANSAS CITY, MISSOURI.

rnorocnarnrc PAPER.

Specification of Letters Patent.

Patented Feb. 11, 1913.

To all whom it may concern:

Be it known that I, FRANK G. WILCOX, a citizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Photographic-Paper; and I do declare the following to be a full, clear,-and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification. a

My invention relates to photographic paper; and it has for its object to produce a photographic paper which shall have a body relatively thin and flexible in crosssection with a sensitive emulsion on both faces and rendered impervious to act-inic rays of light passing through the body of the paper so that printing can be effected upon both surfaces without the sensitive emulsion on one side being fogged or impaired by the action of the-rays of light upon the emulsion upon the other side of the paper, the object also being to have the body-of the paper white in the finished product after printing so that the imprint made upon the paper will be either white or black according as the sensitive coating or emulsion has been darkened or blackened by exposure to actinic raysand subsequent development, thus making a sharp contrast between the color of the paper and the i111 print, one being white and the other black.

In the reproduction 'of documents it is important that it be made possible to print photographically on both sides of a sheet of paper so as to economize in space for filing purposes, and otherwise, it being obvious that if the printing is effected upon only one side of the paper twice the amount of paper will be necessary for a reproduced document and twice the space required forfiling. It is also important that in making imprint upon one side of the paper the sensitive emulsion on the other side of the paper shall be protected against the influence of the actinic rays while printing ,upon one side otherwise the actinic rays will pass through the paper and thus color or fog the emulsion on the opposite side and materially aflect or disturb the efficiency of that emulsion by such coloring or fogging so that a clear imprint cannot be obtained by printing upon that side of the paper. This is particularly so Where the paper is relatively thin and flexible as in paper suitable for photographic purposes. Accordingly it will be appreciated that it is of importance to have the body of the paper flexible or relatively thin in cross-section and with a white surface in the finished product and in which also the sensitive emulsion on one side will be protected from the actinic rays in printing upon the other side having likewise a sensitive emulsion or coating.

To the accomplishment of the foregoing and such other objects as may hereinafter appear I form the paper of relatively thin material with a white body and protect the sensitive emulsion on one side of the paper from the actinic rays acting upon the sensitive emulsion of the other side of the paper by coloring the body of the paper with a suitable coloring substance capable of preventing the actinic rays passing through the body of the paper from one side to the other and of being eliminated or washed out subsequent to the printing step during the developing stage of making the photograph, or otherwise; or by coloring the sensitive emulsion with a suitable coloring substance such as will prevent the actinic rays from passing through the paper to the opposite sensitized surface and as will not materially affect the sensitiveness of the emulsion employed for coating the two sides of the paper, such coloring matter being capable of removal in the subsequent de'veloping or finishing steps in the making of photographic prints; such coloring matter when removed from either the body of the paper or from the sensitive emulsion, leaving the body of the paper white and in contrast with the imprint made by the actinic rays darkening or blackening the port-ions of the emulsion exposed during the printing of the object.

In the accompanying drawings, Figure 1 represents a plan view of a sheet of paper showing a. portion of the sensitive emulsion removed from one side of the paper; and Fig. 2 a transverse section through a sheet of paper showing the sensitive emulsion on both surfaces or faces of the paper; both views being on a magnified scale.

The numeral 1 designates the paper which is by preference made of suitable material having a white body and relatively thin in cross section so as to be light in weight and preferably flexible so as to be capableof being folded. The body of this paper is rendered impervious to actinic rays of light by beingcolored by dyeing or otherwise with a color or dye impervious to actinic rays and such as may be removed subsequent to printing by washing out or by chemicals such as ordinarily employed in the developing or finishing steps of photography. A suitable coloring substance for the purpose is an anilin dye, say of an orange or a red color, such a dye being impervious to actinic rays and not materially affecting the sensitiveness of the emulsion and also being capable of elimination after printing by being washed out in passing the print through the usual developing and printing steps followed in photography.

Both sides of the'paper are coated with sensitive emulsion as indicated by the numeral 2, which in practice will be a rapid emulsion, preferably such as will take an image by light shining through an ordinary negative in about 1/25 to 1/100 of a second, I

more or less, for instance any of the bromid of silver emulsions ordinarily employed in photographic printing by reflection.

Instead of coloring the body of the paper with the dye, I may color the emulsion itself with a dye such as will not materially afiect the sensitiveness of the emulsion and which will prevent the actinic rays directed against the emulsion on one side of the paper from passing through to the sensitive emulsion on the other side, such dye being capable of being removed or washed out in the subsequent developing and finishing steps as ordinarily followed in photography; a dye suitable for the purpose being an anilin dye, preferably orange or red in color. i

A photographic paper made in either of I the ways mentioned will have the characteristics of lightness in weight, relative thinness in cross section, and will prevent the actinic rays which act upon the sensitive emulsion of one side of the paper from passing through so as to seriously affect or fog the sensitive emulsion on the opposite side of the paper, thus making it pos sible to obtain a positive print on each side of the paper without fogging of either side, and in which the coloring matter is capable of being eliminated after the printing has been effected sothat the finished product will present the white body of the paper in strong contrast with the imprint eifected by the darkening or blackening of the emulsion which has been subjected to the actinic rays Paper thus produced has been found to be most satisfactory in the repro duction of documents by the art of photogaway without increasing the bulk beyond I that of the original papers so reproduced.

I have described the best means at present known to me for carrying the invention into practice, buthaving disclosed theessentialcharacteristics of the invention it is obvious that changes might be made in some of the details without departing from the essential characteristics as sought to be defined in the appended claims.

Having described my-invention and set forth its merits what I claim is l. A photographic sheet comprising paper having a sensitive emulsion on opposite sides and containing a coloring matter such as will prevent passage of actinic rays of light from one sensitive surface to the otherysu ch coloring matter being capable of elimination subsequent to the paper being printed upon.

sides, said emulsion containing a coloring matter adapted to prevent passage of actinic rays of light from one sensitlve surface to the other and capable of elimination from- FRANK G. WILCOX.

Witnesses:

W. S. PALMER, Eow. DILLON.

2. A photographic sheet comprising paper havlng a sensitive emulsion on opposite 

